/*
 * Copyright (C) 2016 The Guava Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.common.collect.testing.testers;

import static com.google.common.collect.testing.features.CollectionSize.ZERO;
import static com.google.common.collect.testing.features.MapFeature.ALLOWS_NULL_KEYS;
import static com.google.common.collect.testing.features.MapFeature.ALLOWS_NULL_VALUES;
import static com.google.common.collect.testing.features.MapFeature.SUPPORTS_PUT;

import com.google.common.annotations.GwtCompatible;
import com.google.common.collect.testing.AbstractMapTester;
import com.google.common.collect.testing.features.CollectionSize;
import com.google.common.collect.testing.features.MapFeature;

import java.util.Map;
import java.util.Map.Entry;

import junit.framework.AssertionFailedError;
import org.junit.Ignore;

/**
 * A generic JUnit test which tests {@link Map#computeIfPresent}. Can't be invoked directly; please
 * see {@link com.google.common.collect.testing.MapTestSuiteBuilder}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
@Ignore // Affects only Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
public class MapComputeIfPresentTester<K, V> extends AbstractMapTester<K, V>
{

    @MapFeature.Require(SUPPORTS_PUT)
    public void testComputeIfPresent_supportedAbsent()
    {
        assertNull(
                "computeIfPresent(notPresent, function) should return null",
                getMap()
                        .computeIfPresent(
                                k3(),
                                (k, v) ->
                                {
                                    throw new AssertionFailedError();
                                }));
        expectUnchanged();
    }

    @MapFeature.Require(SUPPORTS_PUT)
    @CollectionSize.Require(absent = ZERO)
    public void testComputeIfPresent_supportedPresent()
    {
        assertEquals(
                "computeIfPresent(present, function) should return new value",
                v3(),
                getMap()
                        .computeIfPresent(
                                k0(),
                                (k, v) ->
                                {
                                    assertEquals(k0(), k);
                                    assertEquals(v0(), v);
                                    return v3();
                                }));
        expectReplacement(entry(k0(), v3()));
    }

    @MapFeature.Require(SUPPORTS_PUT)
    @CollectionSize.Require(absent = ZERO)
    public void testComputeIfPresent_functionReturnsNull()
    {
        assertNull(
                "computeIfPresent(present, returnsNull) should return null",
                getMap()
                        .computeIfPresent(
                                k0(),
                                (k, v) ->
                                {
                                    assertEquals(k0(), k);
                                    assertEquals(v0(), v);
                                    return null;
                                }));
        expectMissing(e0());
    }

    @MapFeature.Require({SUPPORTS_PUT, ALLOWS_NULL_VALUES})
    @CollectionSize.Require(absent = ZERO)
    public void testComputeIfPresent_nullTreatedAsAbsent()
    {
        initMapWithNullValue();
        assertNull(
                "computeIfPresent(presentAssignedToNull, function) should return null",
                getMap()
                        .computeIfPresent(
                                getKeyForNullValue(),
                                (k, v) ->
                                {
                                    throw new AssertionFailedError();
                                }));
        expectReplacement(entry(getKeyForNullValue(), null));
    }

    static class ExpectedException extends RuntimeException
    {
    }

    @MapFeature.Require(SUPPORTS_PUT)
    @CollectionSize.Require(absent = ZERO)
    public void testComputeIfPresent_functionThrows()
    {
        try
        {
            getMap()
                    .computeIfPresent(
                            k0(),
                            (k, v) ->
                            {
                                assertEquals(k0(), k);
                                assertEquals(v0(), v);
                                throw new ExpectedException();
                            });
            fail("Expected ExpectedException");
        }
        catch (ExpectedException expected)
        {
        }
        expectUnchanged();
    }

    @MapFeature.Require({SUPPORTS_PUT, ALLOWS_NULL_KEYS})
    @CollectionSize.Require(absent = ZERO)
    public void testComputeIfPresent_nullKeySupportedPresent()
    {
        initMapWithNullKey();
        assertEquals(
                "computeIfPresent(null, function) should return new value",
                v3(),
                getMap()
                        .computeIfPresent(
                                null,
                                (k, v) ->
                                {
                                    assertNull(k);
                                    assertEquals(getValueForNullKey(), v);
                                    return v3();
                                }));

        Entry<K, V>[] expected = createArrayWithNullKey();
        expected[getNullLocation()] = entry(null, v3());
        expectContents(expected);
    }

    @MapFeature.Require({SUPPORTS_PUT, ALLOWS_NULL_KEYS})
    public void testComputeIfPresent_nullKeySupportedAbsent()
    {
        assertNull(
                "computeIfPresent(null, function) should return null",
                getMap()
                        .computeIfPresent(
                                null,
                                (k, v) ->
                                {
                                    throw new AssertionFailedError();
                                }));
        expectUnchanged();
    }

    @MapFeature.Require(absent = SUPPORTS_PUT)
    public void testComputeIfPresent_unsupportedAbsent()
    {
        try
        {
            getMap()
                    .computeIfPresent(
                            k3(),
                            (k, v) ->
                            {
                                throw new AssertionFailedError();
                            });
        }
        catch (UnsupportedOperationException tolerated)
        {
        }
        expectUnchanged();
    }

    @MapFeature.Require(absent = SUPPORTS_PUT)
    @CollectionSize.Require(absent = ZERO)
    public void testComputeIfPresent_unsupportedPresent()
    {
        try
        {
            getMap().computeIfPresent(k0(), (k, v) -> v3());
            fail("Expected UnsupportedOperationException");
        }
        catch (UnsupportedOperationException expected)
        {
        }
        expectUnchanged();
    }
}
